AC Transit grows to 12 HyRoad zero-emission vehicles
By Rick Fernandez
The combination of petroleum-fuel dependency, air quality problems, and the ominous threat of greenhouse gases has made going green far more consequential than just trendy. The concept is an environmental imperative and a matter of sustainability and national security, and today’s mass transit systems are obliged to pay attention.
No one takes this responsibility more seriously than AC Transit. The California Climate Action certified our agency as a Climate Action Leader for accurately reporting our CO2 emissions. In years past the Environmental and Energy Institute of Washington D.C., and the Bay Area Metropolitan Transportation Commission for our advanced environmental technology initiatives have also recognized AC Transit.
As an enthusiastic proponent of alternative energy and sustainable environments, we have installed solar power arrays at two of our facilities, generating as much as 621 kW of electrical power to support our operations. And we have deployed an expansive recycling plan that includes everything from scrap paper to computer waste.
But the HyRoad program is our most advanced, and perhaps our most significant attempt to further green technology for the public transport industry.
UTC Power fuel cells drive the Van Hool zero-emission HyRoad buses.
It began in 1999 as an initiative to explore the benefits of hydrogen fuel cells and hybrids, and AC Transit subsequently coined the term HyRoad in reference to its work with these cutting edge technologies.
After several years of testing various vehicle options, in March 2006 AC Transit launched a comprehensive Hydrogen Fuel Cell demonstration program, using three zero-emission, fuel cell hybrid buses, powered by UTC Power fuel cell systems that emit only water vapor from the tailpipe. These all-electric vehicles are ultra-quiet and smooth, and extremely fuel efficient, realizing nearly twice the fuel economy of a standard diesel bus. To date, all three buses have logged more than 152,000 miles of service, carrying more than 360,000 passengers.
In addition to the vehicles, AC Transit partnered with Chevron Corporation to build a state-of-the-art hydrogen fueling station that produces 150 kg of hydrogen daily (one kilogram of hydrogen is equal in energy value to one gallon of gasoline).
The fuel cells are compact generators that use an electrochemical reaction between hydrogen and oxygen to produce electricity. As much as 120 kW of power from the fuel cell, plus another 95 kW of power from onboard heavy-duty batteries, are able to propel a 40-ft bus up hills and along major trunkline corridors carrying a full load of passengers.
With 50 kg of hydrogen stored in rooftop vessels, these buses have a range in excess of 300 miles. Onboard heavy-duty batteries provide additional power to assist with hill climbing and acceleration, but also efficiently absorb regenerative braking power whenever the bus reduces its speed on downgrades or before coming to a stop.
Following our initial success, 12 next-generation fuel cell buses are now being manufactured by Van Hool in Belgium with an improved design, complete OEM integration, a better energy storage system that utilizes lithium-ion batteries, and considerably lighter in weight.
As these new buses arrive between September 2009 and June 2010, they will replace the three now in service. While AC Transit will own, maintain and fuel all 12 HyRoad buses, AC Transit, Golden Gate Transit, Valley Transportation Authority, SamTrans, and San Francisco Muni, will jointly operate the fleet in a unique regional demonstration program.
The expanded program will require as much as 420 kg of hydrogen production capacity daily, and will include an expansion of AC Transit’s existing fueling station in Oakland, as well as a new station in the city of Emeryville, where a solar-powered electrolyzer will produce some of the hydrogen supply.
The operation of fuel cell buses results in a considerable reduction in greenhouse gas emissions, ranging from a 43 percent reduction over diesel buses when hydrogen is supplied from the reformation of natural gas, to zero emissions when hydrogen is generated on-site from renewable sources like solar and wind power.
The HyRoad program is now valued at $66 million with funding coming from federal, state and regional alternative fuels research grants, as well as contributions from private sector partners. It is widely considered to be among the most advanced fuel cell demonstrations in the world, and the performance of the vehicles continues to surpass expectations, ushering in a future era of emissions-free transit.
Considering all of this, how can we not be eager to expand our fuel cell operations, further reducing our carbon footprint by transporting our customers in buses that offer decidedly green, advanced technology? As one of the largest transit agencies in California, serving more than 67 million passengers a year throughout a 360-square-mile region, we think the HyRoad program has put us on the right path toward an environmentally sustainable future.
Rick Fernandez serves as general manager for AC Transit, Oakland, CA.